Cellcrypt, a British vendor of software for encrypting cell phone calls, has set up shop in Silicon Valley and is getting a product ready for North America's beloved BlackBerry.

The company sells software to enterprises, government agencies and individuals who want to make sure their mobile phone calls are private. Its Cellcrypt Mobile product is a downloadable, phone-based application that encrypts VoIP (voice over Internet Protocol) calls all the way from one handset to the other. Unlike other cell encryption systems, it allows users to make calls pretty much as they would normally, and even to use international roaming, according to Ian Meakin, Cellcrypt's vice president of marketing.

Versions of Cellcrypt Mobile are already available for Nokia N-Series and E-Series phones and many Windows Mobile devices, and by the end of June the company will introduce a client for BlackBerry phones, Meakin said. Meanwhile, Cellcrypt announced this week it has opened an office in Palo Alto, California, to address growing demand for its products in North and South America, Meakin said. The company develops its software for various platforms using standard tools.

BlackBerry maker Research In Motion, based in Waterloo, Ontario, reported earlier this month it had shipped a record 7.8 million devices in the quarter ended Feb. 28 and surpassed an all-time total of 50 million devices. The BlackBerry is the standard device for users in the high-level executive market that Cellcrypt targets, especially in North America.

Security researchers claim the encryption used for standard GSM (Global System for Mobile Communications) voice traffic has been compromised. Hackers could break into GSM networks in about 30 minutes, with inexpensive tools, and listen to calls from 20 miles away, some researchers said last year.

Cellcrypt avoids this airborne hacking as well as illicit tapping of the wired networks behind cellular base stations, according to Meakin. It avoids the traditional circuit-switched network altogether by using VoIP, and encrypts the VoIP packets with 256-bit AES (Advanced Encryption Standard) and 2048-bit Diffie-Hellman encryption. This encrypts the call all the way from one phone to the other, Meakin said. In addition to cell-to-cell calls, Cellcrypt can be used for calls to fixed-line phones, and the company also offers a gateway application for use with enterprise PBXs (private branch exchanges).

Because it uses VoIP, Cellcrypt Mobile works on any 3G network including the EV-DO (Evolution-Data Optimized) data networks used by U.S. CDMA (Code Division Multiple Access) operators such as Verizon Wireless and Sprint Nextel. The company is also seeking certification under the U.S. National Institute of Standards and Technology's FIPS (Federal Information Processing Standards) 140-2 regulation, which would qualify it for contracts with U.S. government agencies.

Although mobile operators have a sometimes-uncomfortable relationship with VoIP, they don't fear Cellcrypt because it is aimed at a limited market and not designed to help users avoid paying for voice minutes, according to Meakin. The software doesn't come cheap: A license for one user costs about £2,500 (US$3,732) per year, though the price varies based on volume and other factors, Meakin said.

Cellcrypt was founded in 2005 but spent much of its life developing the software to deliver high-quality voice calls with strong encryption, according to Meakin. The company has been selling products widely for only about six months, he said.